According to the Energy Strategy 2050 set forth by the Swiss federal government, Photovoltaic (PV) energy shall make up one fifth of the nation's total energy production in 2050. Such a drastic expansion rate of PV and the resulting excess energy thereof can lead to so-called reverse power flow in the low voltage (LV) grid as demonstrated in previous studies. Power-to-Gas (PtG) represents a suitable storage solution to resolve the situation by absorbing the excess PV energy. This paper presents a qualitative and quantitative feasibility analysis of the PtG technology in the future Swiss LV grid. For this purpose, PtG is integrated in simulation into the grid for absorbing the excess PV energy while producing hydrogen. This hydrogen is assumed to be sold in the mobility sector. Three different operational scenarios are established with respect to the input energy source to the PtG plant, including the excess PV energy, curtailed PV excess energy and PV excess energy plus the energy from the grid. Summing up the results, it can be concluded that the PtG plant is still far from economically viable even though significant improvement can be accomplished to the hydrogen production costs by adopting the active PV curtailment and by purchasing additional energy from the grid. The future study to be undertaken by the authors, with respect to economical viability of the PtG, will include other sources of value, including production of methane as main product, production of oxygen and heat as by-products, and provision of services such as biogas upgrading, frequency regulation and voltage.
This paper presents a qualitative and quantitative feasibility analysis of the Power-to-Gas (PtG) technology in the future Swiss power grid which will be characterized by a significant share of intermittent renewable energy sources (RES), especially Photovoltaic (PV) energy.The Energy Strategy 2050 set forth by the Swiss federal government includes a plan of a strong expansion of renewable energy sources. PV, for example, shall make up one fifth of Switzerland's total energy production in 2050. Such a drastic expansion rate of PV can lead to so-called reverse power flow in the low voltage (LV) grid, as indicated in a previous case study conducted in a Zürich area.This paper demonstrates the impact of the PtG technology through three different scenarios in the above-mentioned case. The scenarios are established with respect to the input energy source to the PtG plant. The PtG plant is integrated into the LV grid for absorbing the excess PV energy for producing hydrogen. For each scenario, the produced hydrogen is assumed to be sold in the mobility sector. The results of this simulation give the insights concerning the technical as well as economical feasibility of the integration of PtG into the existing LV grid.
According to the Energy Strategy 2050 set forth by the Swiss federal government, Photovoltaic (PV) energy shall make up one fifth of the nation's total energy production in 2050. Such a drastic expansion rate of PV and the resulting excess energy thereof can lead to so-called reverse power flow in the low voltage (LV) grid as demonstrated in previous studies. Power-to-Gas (PtG) represents a suitable storage solution to resolve the situation by absorbing the excess PV energy. This report presents qualitative and quantitative feasibility analysis of the Power-to-Gas (PtG) technology in the future Swiss low voltage (LV) grid, which will be characterized by a significant share of intermittent renewable energy sources (RES). For this purpose, a model of producing hydrogen or methane with Photovoltaics (PV) excess energy and additional energy from the grid is established. Data and results from a load flow analysis of a previous study serves as the basis for the analysis. Impact of the PtG technology is demonstrated through nine different operating scenarios established. The input energy source to the PtG plant comprises the excess PV energy and the energy from the grid. Economic values, such as levelized cost of energy (LCOE) and levelized value of electricity (LVOE), are calculated to assess the economic feasibility. Moreover, sensitivity analysis is conducted to identify the parameters having the strongest impact on the electricity cost.
Ambitions to mitigate climate change, increase the pressure to reduce greenhouse gas (GHG) emissions across all sectors of the economy, with significant implications for the energy landscape as well as other emissions sources. Switzerland has committed to reducing its annual direct emissions of GHG by 50% by 2030 compared to 1990. A major share of this reduction shall be achieved domestically while some emissions can be based on measures abroad through the use of international credits. The Swiss government has also formulated the long-term goal to reduce GHG emissions in 2050 by 70-85% compared to 1990 levels (including measures abroad), and to achieve climate neutrality after 2050. Today, domestic GHG emissions in Switzerland originate by about 60% from energy conversion in the transport and building sectors, and by 40 % from other sources including industry. Carbondioxide (CO2) is the major GHG that is emitted with the transport sector being the sector with largest contribution. Given this distribution of GHG emissions, particularly CO2 emissions in the demand sectors attributable to energy conversion and industrial production processes need to be avoided to achieve the climate goals. As of 2017, the Swiss electricity sector is already almost CO2-free as electricity is mainly generated from hydropower (60%), nuclear (32%) renewable and non-renewable combustible energy (5%) and other renewable energy (4%). Future pathways for the developments of the Swiss energy sector are framed by the Swiss Energy Strategy 2050, which aims at discontinuing energy supply from nuclear power plants in Switzerland, and promoting renewable energy and energy efficiency. The transformation of the Swiss energy economy calls for the deployment of new low-carbon energy solutions while maintaining the high level of energy supply reliability, which in particular applies to the electricity sector. One option to provide low-carbon energy services is an increased electrification of energy demand services while using low-carbon generation sources. Against the background of a growing share of variable renewable energy sources in the electricity mix, such as wind and solar energy, the challenges of temporal and spatial balancing of supply and demand is expected to increase in future. Temporal balancing arises due to the inevitable mismatch between renewable electricity production and demand as a consequence of day/night cycles, weather effects and seasonal differences, while spatial balancing is resulting from differences between the locations of electricity production and consumption. A future Swiss energy supply substantially relying on large shares of intermittent electricity generation (mainly photovoltaics and wind power) will need sufficient flexibility options. These must allow for shifting energy between day and night as well as from summer to winter: roof-top PV installations, which exhibit the largest potential for new renewable electricity generation in Switzerland by far, show a distinct seasonal peak in summer and daily peak at noon. These peaks in electricity generation – if not to be curtailed – must either be stored and re-used as electricity at times without sufficient generation, or transformed into other energy carriers such as gases and liquids, which can be used as e.g. transport or heating fuels. In addition to the flexible power plants operated in Switzerland already today, i.e. dam hydro plants and pump storage power plants, increasing the system's flexibility and installing of further flexible power plants and storages becomes inevitable at very high shares of wind and solar PV electricity production in order to operate the electricity system cost-efficiently and to ensure the system's secure operation. A related aspect concerning flexibility options is their location in the system, which, preferably, is close to the Solar-PV generation sites which are often embedded in the consumption centres. There are multiple technologies and measures to avoid CO2 emissions and to increase the energy system's flexibility with Power-to-X (P2X) technologies representing one possible option of the technology portfolio. As defined in this White Paper, the terminology "P2X" refers to a class of technologies that use an electro-chemical process to convert electricity into a gaseous or liquid energy carrier or chemical product (and vice versa), and which may include energy storage. As such, P2X technology not only offers the possibility of enhanced sector coupling between the power sector and energy demand sectors but also to provide short and long-term supply and demand balancing. The objective of the White Paper its supplementary report is to collect the major existing P2X knowledge and to provide a synthesis and evaluation for the Swiss energy market. With the aim to derive a technical, economic and environmental assessment of P2X in the energy system, the gas market, the mobility sector and the electricity market are specifically investigated. Where possible, the White Paper also provides information on applications of P2X technologies in production industries. P2X technology stands for a cluster of technologies which use electricity and other inputs in order to produce other secondary energy carriers. Hence, P2X comprises multiple conversion pathways and energy carriers. In this White Paper we focus on the conversion to hydrogen as well as further gaseous and liquid energy carriers, such as methane, methanol, OME and FT-diesel, as well as the reelectrification where appropriate. For industrial P2X applications further energy carriers/conversion pathways might be included (depending on available information). Since this White Paper focusses on P2X technologies based on chemical conversion processes, technologies for the conversion of electricity with the purpose to produce heat as target product is not in the scope of this White Paper. The White Paper on Power-to-X Technology and its supplementary report emanate from the corresponding project of the Joint Activity of five Swiss Competence Centers for Energy Research (SCCER) funded by Innosuisse with complementary funding from the Swiss Federal Office of Energy (SFOE).
